Is there any environment variable that represents “C:\Documents and Settings” folder or C:\Users folder in Windows?

Is there any environment variable or Other format that the profile path is represented in Windows? I want to query in such a way that I should get the value "C:\Documents and Settings (if windows XP or 2k3) or C:\users (If vista or windows 7).

I dont want the current user name appended to the string, which I can get thru %USERPROFILE% variable.